The present invention relates to an endoscope shaft having a movable distal end portion which is bendable by means of an operating device, and in particular to an endoscope shaft having a plurality of hose members disposed in a decentralized manner.
Endoscopes are instruments especially for exploring hollows or tube-shaped conduits of the body, especially for medical purposes. In particular endoscopes for exploring the esophagus, the stomach, the duodenum from the stomach, the intestine from the anus, the urethra, the vesica and the ureter have become known. Such an endoscope is equipped with a lighting device at its front end and with an optical system for visually detecting the area located in front of the body hollow or body canal to be explored. While until recently the optical information detected ahead of the front end of the endoscope was usually transmitted by means of fiber optics through the endoscope towards its operating portion behind, the insertion of a camera chip at the front endoscope tip as well as the electric image transmission and the illustration of the optical information obtained on a video monitor constitutes the latest prior art now.
Furthermore, endoscopes usually comprise a so-called working conduit through which various working instruments can be introduced and operated. For example, small forceps for taking tissue specimens, biopsy needles, heated cutting wires, small scissors, coagulation electrodes or the like are introduced so as to perform surgical measures at the affected tissue, if need be. Finally, as a rule, a fluid conduit for wash and operating wires for bending the front end of the endoscope in various directions are provided. These operating wires are guided through individual conduits within the endoscope shaft towards the front or distal end thereof, respectively, so as to bend it three-dimensionally by up to 160° in the opposite direction of the endoscope shaft.
In this connection, essential problems arise now, especially with respect to the tactile feeling which is given to the operator during the bending process of the distal end. Therefore, there is the risk that, when the intestine is explored, the intestine wall is injured during the bending process of the distal end. Furthermore, it must be possible to be able to exactly position the distal end in the area to be explored and to be treated, if necessary, which requires a sufficient flexibility as well as at the same time a sufficient stiffness, after the predetermined bending position has been reached.
To solve this problem a prior art device according to DE 100 10 932 A1 is provided to form the distal end portion of a plurality of bellow-shaped disc bodies and/or swelling bodies which are longitudinally juxtaposed and/or stacked, two of which at a time are located diametrically with respect to each other and form a body layer and two longitudinally directly adjacent pairs of bodies of which are phase-shifted by 90°. Thereby, a construction is obtained in which the individual disc-like swelling bodies, seen in the longitudinal direction, are alternately arranged at twelve and six o'clock according to the one layer and at three and nine o'clock according to the neighboring and/or superimposed layer. In this way it is possible to achieve a bend-off of the distal end into the intended direction by correspondingly operating the bellows having the same angular position when they are swelling or contracting, wherein, when the predetermined angular position of the distal end has been reached, the swelling bodies are virtually frozen in this position and thus the position of the distal end is fixed.
Tests have shown in the meantime that the manufacture of a distal end of the aforementioned disc-like swelling bodies is extremely expensive, because they have to be hydraulically interconnected in a fluid-tight manner. The manufacture of the swelling bodies themselves thus is extremely costly and the assembly of the swelling bodies is labor-intense. Therefore the endoscope shaft manufactured in this way is rather unsuited for a throw-away article for reasons of costs.